Factors Predisposing and Triggering the Phenomenon of Shrinkage-Swelling of Clay Soils in the Urban Center of Diamniadio

The phenomena of shrinkage and swelling of clay induce damage to housing structures every year. Precipitation, climatic changes and drought are the cause of wall cracks due to subsidence or swelling of the supporting soil. This movement alters the balance between the soil and the structures. To explain this defection, the soil is made up of three elements: the solid, the liquid and the gas. Sometimes in a natural way or following a human intervention, one of these elements undergoes an abnormal variation that causes the loss of the balance between land and works. It is in this sense that this article deals on the one hand with the factors of predisposition and triggering of the phenomena of shrinkage-swelling of the clay soils of Diamniadio and on the other hand, the factors of aggravation linked to the lithological heterogeneity and the variation in the thickness of the layers susceptible to shrinkage-swelling. The studies carried out have enabled a deeper understanding of the behavior of expansive soils following their interactions with climate, vegetation, hydrology, hydrogeology, constructions among others, but also the influence of lateral and vertical variations of fine soil facies.

Epidemiology of Fetal Death and Analysis of Causes According to CODAC Classification at Amath Dansokho Regional Hospital of Kedougou, Senegal

Objectives: This paper aims to study the epidemiology and causes of fetal deaths in utero at Regional Hospital Amath Dansokho of Kedougou (RHADK). Methodology: This was a retrospective epidemiological study conducted at the Maternity Ward of the Regional Hospital Amath Dansokho of Kedougou from June 01, 2022 to June 30, 2023, including all patients seen for delivery care. Data were analyzed using Statistical Package for Social Science (SPSS 22, Windows version). The parameters studied were the frequency of in-utero fetal death, sociodemographic characteristics, pregnancy and delivery data, neonatal data and cause-of-death classification according to the Cause of Death and Associated Conditions (CODAC) classification. Results: We recorded 1628 deliveries, with 231 cases of in-utero fetal death, a frequency of 14.2%. Fetal death occurred most frequently in multiparous women (64.5%). The majority of patients (72.3%) were transferred. 51.9% of patients with fetal death had at least 3 antenatal visits. On admission, fetal heart rate was absent in 73.2% of patients. The etiology of in-utero fetal death was dominated by maternal factors (high blood pressure, anaemia and diabetes), which accounted for 36.9% of deaths, followed by placental pathologies (retroplacental haematoma) and intrapartum pathologies (uterine rupture, abnormal presentation). Conclusion: In-utero fetal death can be prevented, and is mainly due to direct obstetric complications. The focus should be on the prevention and management of hypertensive disorders and their complications during pregnancy, the fight against anaemia and, above all, the rapid and correct management of dystocia.

Study and Comparison of Swelling and Compressibility Characteristics of Crumb Marl, Flaky Marl with Attapulgite and Sandy Clay from the Diamniadio Urban Pole at the Oedometer

In Senegal, the Diamniadio, Sebikhotane and Bargny sector contains clay soils that are problematic for construction. In order to have more information on the behavior of the clay soils of Diamniadio, free swelling tests followed by load-discharge cycles were carried out according to standard NF P 94-090-1. These tests were carried out using an Oedometric device on the three samples from the study site (sandy clays with calcareous concretion, marls with crumbs and laminated marls with attapulgite) to apprehend their swelling aspects in saturated conditions. For the free swelling test, a determination of the different swelling phases will be carried out followed by a comparison of the rate of evolution of the phases for the three samples from the site. In the same vein, the compressibility characteristics of the samples will also be provided from load-unload Oedometric tests. Thereafter, we proceed to a comparison of the void index at the initial state of the samples after two charge-discharge cycles and the influence of the cycles on the reorganization of the internal structure of the samples. These studies will provide more information on the swelling behavior of Diamniadio soils in the presence of water.